U.S. patent application number 13/405630 was filed with the patent office on 2012-08-30 for resin molded article and display device.
This patent application is currently assigned to KYOWA INDUSTRIAL CO., LTD.. Invention is credited to Tsuneo Matsui, Nobuyuki Take.
Application Number | 20120219757 13/405630 |
Document ID | / |
Family ID | 46719164 |
Filed Date | 2012-08-30 |
United States Patent
Application |
20120219757 |
Kind Code |
A1 |
Take; Nobuyuki ; et
al. |
August 30, 2012 |
RESIN MOLDED ARTICLE AND DISPLAY DEVICE
Abstract
A resin molded article according to the present invention
includes a base portion and an erected wall which is erected from
the base portion, wherein, in an upper end surface of the erected
wall, there is exposed a gate portion formed through an injection
of a resin material during resin molding. Further, in an inner
surface of the erected wall which is opposite from an
externally-appearing side thereof, at opposite portions beside the
gate portion, there is formed a reduction surface which gradually
reduces the erected wall in wall thickness toward the upper end
surface of the erected wall.
Inventors: |
Take; Nobuyuki;
(Higashiosaka-shi, JP) ; Matsui; Tsuneo;
(Sanjo-shi, JP) |
Assignee: |
KYOWA INDUSTRIAL CO., LTD.
Sanjo-shi
JP
SANYO ELECTRIC CO., LTD.
Osaka
JP
|
Family ID: |
46719164 |
Appl. No.: |
13/405630 |
Filed: |
February 27, 2012 |
Current U.S.
Class: |
428/156 |
Current CPC
Class: |
B32B 3/263 20130101;
B32B 2457/20 20130101; Y10T 428/24479 20150115; Y10T 428/24777
20150115 |
Class at
Publication: |
428/156 |
International
Class: |
B32B 3/00 20060101
B32B003/00 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 28, 2011 |
JP |
2011-043025 |
Claims
1. A resin molded article comprising a base portion and an erected
wall which is erected from the base portion, wherein, in an upper
end surface of the erected wall, there is exposed a gate portion
formed through an injection of a resin material during resin
molding, and in an inner surface of the erected wall which is
opposite from an externally-appearing side thereof, at opposite
portions beside the gate portion, there is formed a reduction
surface which gradually reduces the erected wall in wall thickness
toward the upper end surface of the erected wall.
2. The resin molded article according to claim 1, wherein the gate
portion protrudes from the reduction surface, and this protruding
portion is positioned at its vertex on the inner surface of the
erected wall and exposes an inverted-conical-shaped outer
peripheral surface extending in a fan shape from this vertex toward
an upper end surface of the gate portion.
3. A display device employing the resin molded article according to
claim 1.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This patent application claims priority from Japanese Patent
Application No. 2011/43025, which is herein incorporated by
reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to resin molded articles, such
as cabinets forming display devices.
[0004] 2. Description of the Related Art
[0005] In general, a casing of a television receiver, as a display
device, is formed from a front cabinet and a back cabinet which are
coupled to each other, wherein the front cabinet is constituted by
a front-surface wall having a larger opening for exposing a screen,
and a peripheral wall surrounding the front-surface wall, for
example.
[0006] Such a cabinet is fabricated through resin molding, using a
die constituted by a pair of die members 91, 92 as illustrated in
FIG. 7.
[0007] The pair of the die members 91, 92 are combined with each
other to form a cavity 93 to be filled with a resin material,
between both the die members 91, 92. This cavity 93 includes a
first cavity portion 94 for forming a front-surface wall of a
cabinet, and a second cavity portion 95 for forming a peripheral
wall of the cabinet.
[0008] On the other hand, among resin molding methods using dies,
there have been known direct-gate methods adapted to directly
inject resin materials into a cavity 93 through a direct gate 9, as
illustrated in FIG. 7, without providing a sprue or a runner.
[0009] In a case of performing molding for a cabinet, according to
a direct-gate method, a resin material is flowed, at first, through
a direct gate into a column-shaped space, the resin material is
charged into this column-shaped space and is solidified therein,
and a portion 8 thereof (hereinafter, referred to as a gate
portion) is formed in an erected wall 7 forming a peripheral wall
of the cabinet, as illustrated in FIG. 6.
[0010] With the direct-gate method, it is possible to save the
resin material by an amount corresponding to the volume of a sprue
or a runner.
[0011] However, as illustrated in FIG. 7, in a case of directly
installing the direct gate 9 at the upper end of the cavity portion
95 for forming an erected wall and, further, injecting a resin
material thereinto through the direct gate 9, particularly when the
erected wall has a larger wall thickness, the resin material flows
into the cavity portion 95 through the direct gate 9 along an
unstable flow path, thereby inducing the problem of occurrences of
drawbacks in the external appearance, such as flow marks on the
surface of the resin molded article.
SUMMARY OF THE INVENTION
[0012] According to the present invention, there is provided a
resin molded article including a base portion and an erected wall 4
which is erected from the base portion, wherein, in an upper end
surface of the erected wall 4, there is exposed a gate portion 5
formed through an injection of a resin material during resin
molding.
[0013] Further, in an inner surface 41 of the erected wall 4 which
is opposite from an externally-appearing side thereof, at opposite
portions beside the gate portion 5, there are formed reduction
surfaces 51, 51 which gradually reduce the erected wall 4, in wall
thickness, toward the upper end surface of the erected wall 4.
[0014] In a resin-molded-article fabricating method according to
the present invention, a die for use in resin molding includes a
cavity 63 for forming the erected wall 4 and, in this cavity 63, in
a die surface for forming the inner surface 41 of the erected wall
4 which is opposite from the externally-appearing side, there are
provided reduction-surface formation portions 67 for forming the
reduction surfaces 51, 51 for gradually reducing the wall thickness
of the erected wall 4 toward the upper end surface of the erected
wall 4, at opposite portions beside the position at which the gate
portion 5 is to be formed.
[0015] In the resin-molded-article fabricating method according to
the present invention, a resin material is injected into the cavity
63, using a direct gate 6.
[0016] As a result thereof, the erected wall 4 is formed. At this
time, due to the reduction-surface formation portions 67 in the
cavity 63, the reduction surfaces 51, 51 are formed, in the inner
surface 41 of the erected wall 4 which is opposite from the
externally-appearing side, at opposite portions beside the gate
portion 5, such that the reduction surfaces 51, 51 gradually reduce
the wall thickness of the erected wall 4 toward the upper end
surface of the erected wall 4.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a perspective view of a television receiver to
which the present invention should be applied;
[0018] FIG. 2 is a partially-broken perspective view of a front
cabinet to which the present invention is applied;
[0019] FIG. 3 is a plan view illustrating main portions of the
front cabinet;
[0020] FIG. 4 is a perspective view illustrating main portions of
the front cabinet;
[0021] FIG. 5 is a cross-sectional view illustrating main portions
of a die for use in resin molding according to the present
invention;
[0022] FIG. 6 is a perspective view illustrating a portion of a
front cabinet in a related art; and
[0023] FIG. 7 is a cross-sectional view illustrating main portions
of a die for use in resin molding in a related art.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0024] Hereinafter, with reference to the drawings, there will be
described, in detail, an embodiment where the present invention is
applied to a display device, more specifically, to a television
receiver.
[0025] As illustrated in FIG. 1, the television receiver according
to an embodiment of the present invention includes a casing formed
from a front cabinet 1 and a back cabinet 2 which are coupled to
each other, wherein the front cabinet 1 is constituted by a base
wall 3 forming a front-surface wall having a large opening for
exposing a screen 11, and an erected wall 4 forming a peripheral
wall surrounding the front-surface wall.
[0026] The front cabinet 1 is fabricated, through resin molding
according to a direct gate method, using a die constituted by a
combination of a pair of die members 61, 62 illustrated in FIG.
5.
[0027] In resin molding processing, the pair of the die members 61,
62 are combined with each other to form a cavity 63 between both
the die members 61, 62, and a resin material is directly injected
into the cavity 63 through a direct gate 6.
[0028] Further, in resin molding for the front cabinet 1
illustrated in FIG. 1, a resin material is injected into the cavity
63 through plural direct gates 6.
[0029] FIGS. 2 to 4 illustrate portions around a gate portion 5
formed through the injection of the resin material through the
direct gate, in the front cabinet 1 formed through the resin
molding using the die.
[0030] The front cabinet 1 includes the erected wall 4 which is
erected from the base wall 3 as described above, wherein, in the
upper end surface of this elected wall 4, there is exposed the gate
portion 5 formed through the introduction of the resin material
during the resin molding.
[0031] In the inner surface 41 of the erected wall 4 which is
opposite from its externally-appearing side, there are formed
reduction surfaces 51, 51 which gradually reduce the wall thickness
of the erected wall 4 toward the upper end surface of the erected
wall 4, at opposite portions beside the gate portion 5.
[0032] The reduction surfaces 51, 51 are formed from inclined
surfaces intersecting, at a small angle, with the inner surface 41
of the erected wall 4, arc-shaped surfaces smoothly continuous with
the inner surface 41, or a combination of such inclined surfaces
and arc-shaped surfaces. There is no level difference at the
boundary portions between the reduction surfaces 51, 51 and the
inner surface 41.
[0033] Further, the gate portion 5 protrudes, at a portion thereof,
from the reduction surfaces 51, 51, and this protruding portion is
positioned at its vertex on the inner surface 41 of the erected
wall 4 and exposes an inverted-conical-shaped outer peripheral
surface extending in a fan shape from this vertex toward the upper
end surface of the gate portion 5.
[0034] In order to perform resin molding for the front cabinet 1,
the die illustrated in FIG. 5 is provided, in the cavity 63
thereof, with a gate-portion formation portion 66 for forming the
gate portion 5.
[0035] Further, in this cavity 63, in the die surface for forming
the inner surface 41 of the erected wall 4, there are provided
reduction-surface formation portions 67 for forming the reduction
surfaces 51, 51, at opposite portions beside the gate-portion
formation portion 66.
[0036] In the processing for performing the resin molding for the
front cabinet 1 using the die, since a second cavity portion 65 for
forming the erected wall 4 is made narrower in the wall-thickwise
direction, due to the reduction-surface formation portions 67, the
resin material injected into the second cavity portion 65 through
the direct gate 6 is flowed along the reduction-surface forming
portions 67, thereby stabilizing the flow path thereof.
[0037] This can suppress the occurrence of drawbacks in the
external appearance, such as flow marks induced during the resin
molding for the front cabinet 1.
[0038] It should be noted that the configuration of each portion
according to the present invention is not restricted to the
embodiment described above, and those skilled in the art could make
various modifications without departing from the spirit of the
present invention described in the claims. Further, the present
invention can be applied to various types of resin molded articles
having erected walls, as well as to the front cabinets of
television receivers.
* * * * *